Search

BACKGROUND: Nerve growth factor (NGF) has an inhibitory effect on normal neuronal apoptosis, thereby improving the ability to repair cell damage, and playing a therapeutic role in some autoimmune diseases. OBJECTIVE: To observe the effect of recombinant adeno-associated virus mediated nerve growth factor (Ad-NGF) on apoptosis and myelination of oligodendrocytes in experimental autoimmune encephalomyelitis (EAE) mice. METHODS: Thirty female healthy C57BL/6 mice were randomly divided into normal group, EAE group and transfection group, with 10 mice in each group. In the EAE group and transfection group, EAE models were made in mice using myelin oligodendrocyte glycoprotein peptide immunoassay. Three days after modeling, mice in the EAE group were injected normal saline via the tail vein for 21 continuous days, while those in the transfection group were injected Ad-NGF via the tail vein for 21 continuous days. All the mice were executed at the peak period of the disease. LFB staining was used to observe the morphology and pathology of myelin tissue. Immunofluorescence method was used to observe the expression and co-localization of apoptotic protein Caspase3 and oligodendrocytes in spinal cord tissue. RT-PCR method was used to detect the mRNA levels of NGF and myelin alkali in spinal cord tissue. Western blot assay was used to detect the protein levels of NGF and Caspase3 in spinal cord tissue. ELISA was used to measure the level of myelin basic protein in spinal cord tissue. The study protocol was approved by the Animal Ethics Committee of Southwest Medical University (approval No. 201912-8). RESULTS AND CONCLUSION: LFB staining showed significant demyelination changes in the EAE group, while the demyelination was significantly improved in the transfection group. Caspase-3 aggregation was obviously observed in oligodendrocytes of EAE group, but not in transfection group. RT-PCR results indicated that the mRNA levels of myelin basic protein and NGF were significantly lower in the EAE group than the normal control and transfection groups (P < 0.05). Western blot results revealed that in the EAE group the level of Caspase3 protein was significantly increased (P < 0.05), while the level of NGF significantly reduced as compared with the normal control and transfection groups (P < 0.05). ELISA results showed that the level of myelin basic protein in the EAE group was significantly lower than those in the normal control and transfection groups (P < 0.05). To conclude, the Ad-NGF transfected by external turnover has preventive and control effects on the EAE mouse model, and its mechanism may be related to upregulation of NGF level, down-regulation of Caspase3 in oligodendrocytes, and promotion of myelin basic protein expression, thereby improving demyelination. [ABSTRACT FROM AUTHOR]

BACKGROUND: There is no systematical report on the conserved structure, protein characteristics and phylogenetic relationship of the Fasciclin gene family OBJECTIVE: To investigate the evolutionary history of the Fasciclin gene family, and to systematically analyze the conservative structure, protein characteristics, and phylogenetic relationships of this gene family METHODS: Based on the published genome data of eight species such as people, chimpanzee and zebrafish, HMM models were established using the HMMER software to analyze the characteristics and genetic structure, structure domain and biochemical characteristics, evolutionary relationships and expression characteristics of the Fasciclin gene family. RESULTS AND CONCLUSION: In the eight species of fish (zebrafish), amphibian (xenopus), bird (chicken), reptile (Trionyx sinensis), mammal (rat, mouse) and primate (chimpanzee, human), 5, 5, 4, 5, 5, 4, 4, and 4 fasciclin candidate genes were retrieved respectively. Through the phylogenetic analysis of the fasciclin gene in these eight species, the evolutionary tree of fasciclin gene families can be divided into four evolution branch. The two branches of all are more conservative, likely to be the main osteoblast specific factor; the third branch may be osteoblast specific factor of amphibians, mammals and primate; and the final branch also has a good conservative, but the Xenopus and mouse in the branch has two copies of the genes, and this branch may play an important role in the evolution of these two species. Overall, in the evolution of species, the gene family has no larger changes, and such genes may be important for the growth and development. The lack of such genes may lead to the death of the individual or the extinction of species. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Mesenchymal stem cells transplantation is a promising treatment for spinal cord injury. Most of studies focused on small animal models. In large animal experiments, there are still controversies in selection of stem cells and therapeutic effect. This article analyzed the effects of mesenchymal stem cells on related indicators of spinal cord injury in large animal models and evaluated their effects on spinal cord injury repair. METHODS: PubMed, Cochrane, OVID, Web of Science and CNKI databases were retrieved before December 2019. A series of studies on the treatment of spinal cord injury in large animal models by mesenchymal stem cells were collected. According to the inclusion criteria, two researchers independently completed literature screening, data extraction and methodological quality evaluation, and meta-analysis was conducted with Stata16.0. RESULTS: A total of 10 articles were included. The results of meta-analysis showed that: (1) Mesenchymal stem cells could significantly improve motor function after spinal cord injury [I2=97.73%, MD=3.94, 95%CI (2.15, 5.72), P < 0.01]. Based on cell source, observation time, intervention phase, transplantation mode and graft type subgroup analysis showed that motor scores of bone marrow mesenchymal stem cells group, non-bone marrow mesenchymal stem cells group, short-term observation (< 2 months) group, long-term observation (≥ 2 months) group, acute stage group, non-acute stage group, cells group and allograft group were significantly higher than those of control group (P < 0.01). There was no significant difference in motor score between scaffold group and control group (P > 0.05). (2) The injury size in mesenchymal stem cells treatment group was significantly smaller than that in the control group [I2=98.05%, MD=-1.00, 95%CI (-1.95, -0.04), P=0.04]. (3) There was no significant difference in the relative expression of glial fibrillary acidic protein between the mesenchymal stem cells treatment group and the control group [I2=99.48%, MD=80.61, 95%CI (-27.48, 188.70), P=0.14]. CONCLUSION: Mesenchymal stem cells transplantation has a significant improvement on the motor function and injury repair of spinal cord injury in large animals, and the security is high. Due to the limitation of the quality of the included literature, the above conclusions need to be validated by high-quality and large-sample randomized controlled trials. [ABSTRACT FROM AUTHOR]

BACKGROUND: There are increasing reports about autophagy, but the relationship between the level of autophagy in neurons and the neuroprotection mechanism is not clear. OBJECTIVE: To investigate whether rapamycin, an mammalian target of rapacmycin (mTOR) autophagy pathway inhibitor, could activate autophagy by mediating the P70s6k and mTOR protein levels to protect spinal cord neurons in experimental autoimmune encephalomyelitis mice. METHODS: Fifty-four healthy female C57BL/6 mice were divided into three groups: control group, model group and treatment group, with 18 mice in each group. Mice in the model group and treatment group were injected with complete Freund’s adjuvant containing MOG35-55 and pertussis diluent for establishing models of experimental autoimmune encephalomyelitis. At the same time, the mice in the treatment group were given rapamycin (1 mg/kg per day), and those in the model and control groups were given the same amount of normal saline. The mice in the model and treatment were sacrificed at the peak of the onset, and the non-morbid mice, including those in the control group, were sacrificed after 4 weeks of feeding. The spinal cord tissue from each animal was taken to isolate the intumescentia lumbalis of the spinal cord. Nissl staining was used for pathological observation of the spinal cord tissue. Immunofluorescence double staining was used to observe the expression and co-localization of autophagy markers LC3 and NeuN in spinal cord tissue. Western blot was used to detect mTOR, P70S6K proteins and their phosphorylation levels in spinal cord tissue. RESULTS AND CONCLUSION: No mice in the control group had an attack, but those in the other groups developed experimental autoimmune encephalomyelitis to different extents. Compared with the model group, the treatment group had prolonged incubation time (P < 0.01), shortened progressive stage (P < 0.01), and decreased neurologic dysfunction score (P < 0.05). Compared with the control group, the model group had the significantly less number of Nissl bodies (P < 0.05), while the number of Nissl bodies in the treatment group was significantly higher than that in the model group, but still lower than that in the control group (P < 0.05). In the model group, LC3 was scattered in the spinal cord neurons and had no obvious dot-like aggregation, whereas in the treatment group, LC3 showed obvious dot-like aggregation, and its distribution was basically consistent with that of NeuN. The phosphorylation levels of mTOR and P70S6K proteins were highest in the model group, followed by the treatment group and control group in turn. To conclude, rapamycin might through inhibiting the phosphorylation levels of mTOR and P70S6K proteins activate the activity of autophagy to protect the spinal cord neurons in experimental autoimmune encephalomyelitis mice. [ABSTRACT FROM AUTHOR]

BACKGROUND: Acupuncture and hot compress of traditional Chinese medicine therapy have good curative effect on degenerative diseases of the intervertebral disc; however, the combination effect of these two methods on the apoptosis of intervertebral disc cells remains unclear. OBJECTIVE: To explore the effects of Tongbi prescription hot compress combined with acupuncture on the mRNA expression of apoptosis-related genes, Caspase-3 and Bcl-2, in intervertebral disc cells in a rabbit model of cervical spondylosis. METHODS: Twenty-four rabbits were randomly divided into normal group, model group, acupuncture group and combination treatment group, with six rabbits in each group. Except for the normal group, animal models of cervical spondylosis were established in the other three groups. After successful modeling, acupuncture treatment (30 minute once a day) and Tongbi Recipe hot compress combined with acupuncture therapy (30 minutes once a day) were done in the acupuncture group and combination treatment group, respectively. The cervical spine X-ray of each rabbit was taken and scored before modeling, at 30 days after molding as well as at the end of the treatment. The C3-4 and C4-5 intervertebral discs of each group were collected after treatment for 15 times. Hematoxylineosin staining was used to observe the morphological changes of C3-4 discs, and real-time quantitative PCR was used to detect the relative expression of Caspase-3 and Bcl-2 mRNA in C4-5 intervertebral discs. The study protocol was approved by the Animal Ethics Committee of Guizhou Medical University. RESULTS AND CONCLUSION: Compared with the model group, the cervical spine lesions in the acupuncture group and combination treatment group were significantly reduced, with a significant reduction in the X-ray scores (P < 0.05). However, there was no significant difference between these treatment groups. The injury of intervertebral disc tissue and scores in the acupuncture group and combination treatment group were lower than those in the model group, and the score of the combination treatment group was significantly lower than that of the acupuncture group (P < 0.05). Compared with the model group, the expression of Casepase-3 mRNA decreased and the expression of Bcl-2 mRNA increased in the acupuncture group and combination treatment group, and the combination treatment group had lower Casepase-3 mRNA expression and higher Bcl-2 mRNA expression than the acupuncture group (P < 0.05). To conclude, Tongbi prescription hot compress combined with acupuncture therapy can delay the degeneration of intervertebral disc, and its mechanism may be related to the up-regulation of Bcl-2 mRNA expression and down-regulation of Casepase-3 mRNA expression. [ABSTRACT FROM AUTHOR]

BACKGROUND: Studies have shown that cornuside I (Cor I) can promote the proliferation of osteoblasts and chondrocytes, but its role and mechanism in repairing early cartilage damage of knee osteoarthritis are not clear. OBJECTIVE: To investigate the effect of Cor I on knee osteoarthritis rats and its effect on interleukin-6 (IL-6)/JAK2/STAT3 signaling pathway. METHODS: Fifty healthy male Sprague-Dawley rats were randomly divided into sham operation group, knee osteoarthritis model group (model group), Cor I high-dose group (Cor I-H), and cornuside I low-dose group (Cor I-L) and positive control group (celecoxib), with 10 rats in each group. Except the sham operation group, the knee osteoarthritis rat model was prepared according to the Hulth method. The Cor I-L and Cor I-H groups were administrated with Cor I 1.25 and 5 g/kg once a day for 6 weeks after modeling. The positive control group was fed with 4 mg/kg celecoxib, and the sham operation and model groups were fed with the same amount of normal saline once a day. The rats were sacrificed by cervical dislocation 24 hours after the last administration. Hematoxylineosin staining was used to observe the pathological and morphological changes of articular cartilage tissue in rats, and the degree of cartilage degeneration was scored according to Mankin’s method. Interleukin-1β, tumor necrosis and matrix metalloproteinase-13 in rat cartilage tissue were detected by ELISA. Interleukin-6 and STAT3 protein expression in rat articular cartilage tissue were detected by immunohistochemistry. Relative expressions of JAK2, p-JAK2, STAT3, and p-STAT3 were detected by western blot. RESULTS AND CONCLUSION: The articular cartilage of rats was severely damaged in the model group, where obvious chondrocyte damage and disordered arrangement of chondrocytes were observed. The joint structure of the rats in the Cor I-H, Cor I-L and positive control groups tended to be normal, the chondrocytes were distributed uniformly, and the fissures were reduced. Compared with the model group, the relevant indicators in the Cor I-L and Cor I-H groups were significantly reduced, including the Mankin’s score of cartilage tissue, interleukin-1β, tumor necrosis factor α and matrix metalloproteinase-13 levels (P < 0.05), interleukin-6 and STAT3 immunoreactivities (P < 0.01) as well as the relative expression levels of p-JAK2 and p-STAT3 and ratios of p-JAK2/JAK2 and p-STAT3/STAT3 (P < 0.05). Compared with the positive control group, these indicators mentioned above were significantly increased in the Cor I-L group (P < 0.05); however, there was no significant difference between the positive control group and Cor I-H group. Results have confirmed that Cor I can delay knee osteoarthritis-induced cartilage tissue degeneration, and its mechanism may be related to reducing the were expression of inflammatory factors and inhibiting the inflammatory response mediated by interleukin-6/JAK2/STAT3 signaling pathway. [ABSTRACT FROM AUTHOR]

BACKGROUND: Although extracellular signal-regulated kinase 5 (ERK5) is an essential transducer of external signals for osteoblasts growth, differentiation, and survival, the effects of ERK5 signaling on bone homeostasis in vivo have not yet been described. OBJECTIVE: To elucidate whether the inhibition of ERK5 activity and its downstream targets by XMD8-92 results in osteoporosis and aggravates dexamethasoneinduced osteoporosis. METHODS: In vivo experiment: A mouse model of osteoporosis was induced by dexamethasone. There were four groups: blank control group (PBS); XMD8-92 group (50 mg/kg); dexamethasone group (50 mg/kg); XMD8-92+dexamethasone group (50 mg/kg XMD8-92 plus 50 mg/kg dexamethasone). Administration was done for 5 continuous weeks. Cell experiment: There were four groups: blank control group; XMD8-92 group (5 μmol/L); dexamethasone group (10×10-6 mol/L); XMD8-92+dexamethasone group (treatment with 5 μmol/L XMD8-92 followed by 10×10-6 mol/L dexamethasone). Cells were incubated for 1 hour. In addition, ERK5 activation was induced using epidermal growth factor. ERK5 activity in mice and MC3T3-E1 cells were detected. We further detected bone mass, bone architecture and mechanical stress of the trabecular bone, measured the expression of receptor activator of nuclear factor-κB ligand/osteoprotegerin (RANKL/OPG) and observed the roles of XMD8-92 in osteoblast proliferation and apoptosis. The study protocol was approved by the Ethics Committee of the Second Hospital of Lanzhou University (No. 2016-D44). RESULTS AND CONCLUSION: XMD8-92 could block ERK5 phosphorylation, change the architecture of the trabecular bone, reduce bone mass and aggravate dexamethasone-induced osteoporosis. XMD8-92 could significantly reduce the biomechanical properties of bone tissues in mice. XMD8-92 could up-regulate RANKL/OPG rate, lower osteoblasts vitality by inhibiting Cyclin B1 and CDK1 expression, and promote osteoblast apoptosis by up-regulating the expression of FasL. The novel findings suggest that ERK5 activity plays an important role in maintenance of bone mass, and altered ERK5 activation in disease conditions such as osteoporosis or dexamethasone-induced osteoporosis should be considered as a potential mechanism for abnormal bone homeostasis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Osteoporotic fractures are the most common serious complications caused by osteoporosis, and their repair is more difficult, which seriously threatens the health and quality of life of patients. OBJECTIVE: To investigate the interventional effect of Panax Notoginsenosides in ovariectomized osteoporotic fracture rats and the relevant mechanism. METHODS: Fifty healthy female rats were selected. Ten of them were normal group, and the other 40 rats were used to make ovariectomized osteoporotic fracture models. Model rats were divided into model group, low, medium and high dose group. Normal group and model group rats were intragastrically administered normal saline, rats in the low, medium and high dose group were given intragastric administration of 10, 20 and 40 mg/kg Panax Notoginsenosides solution. The study protocol was approved by the Animal Ethic Committee of the First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, No. (2019)58 on September 23, 2019. RESULTS AND CONCLUSION: The bone mineral density and bone cell index of the high dose group were higher than those of low and middle dose groups (P < 0.05). The bone volume fraction, the number of callus trabeculae and the thickness of trabeculae in the high dose group were all higher than those in the model group, the low dose group and the middle dose group, and the resolution of trabeculae was lower than that in these three groups (P < 0.05). The levels of glutathione peroxidase, bone morphogenetic protein 2, and vascular endothelial growth factor in the high dose group were lower than those in the normal group, but higher than those in the model group, low and medium dose groups. The levels of lipid peroxide, malondialdehyde, osteocalcin, type I procollagen carboxy terminal propeptide, bone-specific alkaline phosphatase in the high dose group were higher than those in the normal group, but lower than those in the model group, low and medium dose group (P < 0.05). The expression of PI3K, Akt and mTOR in the low, middle and high dose groups was lower than that in the normal group and higher than that in the model group; and the expression of PI3K, Akt and mTOR in the high dose group was higher than that in the low and middle dose groups (P < 0.05). Therefore, treatment with Panax Notoginsenosides can increase the bone miner density and bone cell index, promote the growth of bone trabecula at the callus, alleviate oxidative stress injury, regulate the PI3K / Akt / mTOR signal pathway, and accelerate the formation of new blood vessels in the callus and fracture healing in ovariectomized osteoporotic fracture rats. [ABSTRACT FROM AUTHOR]

BACKGROUND: Melatonin, a neuroendocrine hormone, is mainly secreted by the pineal gland, which can promote the proliferation of Schwann cells and the regeneration of peripheral nerve after injury. OBJECTIVE: To investigate the role of melatonin in the migratory activity of Schwann cells together with the molecular mechanism involved. METHODS: The rodent RSC96 Schwann cell line was cultured in vitro followed by identification. The CCK-8 assay was performed to detect the effect of melatonin on Schwann cells proliferation. The Transwell chamber was adopted to observe the efficacy of melatonin with a series of concentrations, which is 0, 100 nmol/L, 1 μmol/L and 10 μmol/L, on the migratory activity of Schwann cells following 20 hours. The expression of melatonin receptor 1 and 2 in Schwann cells was assessed using qRT-PCR and western blot assay. Transwell cell migration system was conducted to determine the influence of melatonin receptor antagonist luzindole or inhibitor IWR-1 of the canonical Wnt/β-catenin signaling on the enhanced migratory activity exerted by melatonin. Western blot assay was performed to investigate the regulatory effect of melatonin on the activity of Wnt/β-catenin signal cascades. RESULTS AND CONCLUSION: (1) The cultured RSC96 cells showed the typical morphology of Schwann cells, showing a spindle-like or triangular shape with thin and long processes on the two cell poles. The Schwann cells marker S-100 immunofluorescence staining was positive. (2) Compared with the blank control group, 1 μmol/L and 10 μmol/L melatonin could promote Schwann cell migration dramatically compared to the control group, and displayed a chemoattractive effect, with 1 μmol/L showing the most significant effect. (3) Melatonin receptor 1 was the dominating receptor of melatonin expressed in Schwann cells. The Transwell assay results displayed that the number of migratory cells that melatonin induced was not significantly changed with luzindole added, as compared with treatment with melatonin alone, showing no statistical significance. The number of Schwann cells treated with IWR-1 and melatonin was significantly lower than those treated with melatonin (P < 0.05). (4) Results of qRT-PCR and western blot assay showed that compared with the blank control group, the expression levels of P-Lrp6, LEF-1 and nuclear β-catenin protein in Schwann cells of melatonin group were significantly increased (P < 0.05). (5) The expression levels of LEF-1 and nuclear β-catenin protein in Schwann cells of melatonin group and IWR-1 + melatonin group were significantly higher than those of blank control group and IWR-1 group (P < 0.05), indicating that melatonin can antagonize the inhibition of IWR-1 on Wnt/β-catenin signaling pathway activity to some extent. (6) The above data confirm that melatonin can promote Schwann cell migration by activating Wnt/β-catenin signaling pathway. [ABSTRACT FROM AUTHOR]

BACKGROUND: As a mature method of decellularization at present, descaling agent has the advantages of simple operation, small damage, and easy control of experimental conditions. Some studies have combined different descaling agents to achieve good results in decellularization. OBJECTIVE: To compare the effect of two descaling agents and the immune response of two kinds of acellular vascular materials subcutaneously implanted into animals. METHODS: Two methods were used to treat the porcine carotid artery for descaling agent. One group was treated in the mixed solution of 1% sodium dodecyl sulfate and 1% sodium deoxycholate for 72 hours; the other group was treated in the mixed solution of 1% sodium dodecyl sulfate and 1% Triton X-100 for 72 hours. After cell removal, histological analysis, scanning electron microscope analysis, mechanical analysis and DNA content detection were carried out. Two groups of acellular vascular materials were implanted subcutaneously in the back of SD rats. After 1, 2, 4 and 8 weeks, the grafted vascular materials were taken out for hematoxylin and eosin and immunofluorescence staining. This study was approved by the Animal Ethics Committee of Jiangnan University. RESULTS AND CONCLUSION:(1) Histological analysis showed that 1% sodium dodecyl sulfate combined with 1% sodium deoxycholate effectively removed the cell components and retained the extracellular matrix structure, and the effect of cell removal was better than 1% sodium dodecyl sulfate combined with 1% Triton X-100.(2) The DNA content of 1% sodium dodecyl sulfate combined with 1% sodium deoxycholate group was significantly lower than that of 1% sodium dodecyl sulfate combined with 1% Triton X-100 group(P < 0.05). There were no significant differences in bursting strength and suture tolerance between the two schemes(P > 0.05).(3) Scanning electron microscopy showed that 1% sodium dodecyl sulfate combined with 1% Triton X-100 significantly damaged the extracellular matrix compared with 1% sodium dodecyl sulfate combined with 1% sodium deoxycholate.(4) In the subcutaneous implantation experiment, a large number of inflammatory cells infiltrated around the carotid artery materials of the two groups at 1 week after operation. No inflammatory cells infiltrated around the acellular materials of 1% sodium dodecyl sulfate and 1% sodium deoxycholate at 8 weeks after operation. Lymphocyte infiltrated around the acellular materials of 1% sodium dodecyl sulfate and 1% Triton X-100 group. 1% sodium dodecyl sulfate combined with 1% Triton X-100 acellular material mainly induced macrophages to differentiate into M1 type. 1% sodium dodecyl sulfate combined with 1% sodium deoxycholate acellular material mainly induced macrophages to differentiate into M2 type.(5) Compared with 1% sodium dodecyl sulfate and 1% Triton X-100, 1% sodium dodecyl sulfate and 1% sodium deoxycholate are more promising cell-free treatment. [ABSTRACT FROM AUTHOR]